Cannot upload documents in Library with a Date Column created through the Library UI

Probably inner-ring tenants, observed on two demo tenants and one paid tenant. Have been observing for approximately a week.

DESCRIPTION:

In SPO, if a Date Column with a default value is added to a Library using the "Add Column" option available from the Library page (As opposed to adding a column via the Library Settings page), it is no longer possible to upload documents or create folders in the library.

REPRO STEPS:

• Create a new Document Library
• Using the "+ Add Column" button, create a a Date Column. Set the name to "DateColumn" and use the Default Value drop-down to select a date in the past. Click Save
• Attempt to create a folder, note the error message: "Cannot create folder "<path>""
• Attempt to upload a document, note the error message "The URL '<path>' is invalid. It may refer to a nonexistent file or folder, or refer to a valid file or folder that is not in the current Web."

NOTES:
Can work around the issue by creating a column via Library Settings instead of straight from the Document Library.